I find the best remedy for discolored enamal, stained formica, brown cooked on spots on skillets, and dozens of other household stains, is baking soda. For mild discoloration, it can be used as cleanser--sprinkled on, and scrubbed with a non-abrasive scrubber. For more serious problems, I make a paste, spread it on, let it sit a bit, then scrub. Last week, dd burned a pan badly (fortunately, it wasn't one of my good pans)--so I just put some water and baking soda in it, boiled it about 10 minutes, then ran it through the dishwasher. It's good as new.

I like that Baking soda is non-abrasive, non-toxic, anti-bacterial, natural, cheap, readily available. And most of all--that it's pretty much the most effective cleaner I've found for a lot of things.

I have some very old Le C ovens and such and most of the older ones are brownish...they just get that way. I don't think it's tomato at all...but rather a spoon abrading the bottom of the pot and allowing discoloration.
If the bottom feels smooth, I ignore it...if there is "something" on it I do the baking soda soak and end up with a magic sponge.
Linda C

I have several pieces of LC. The biggest problem I have with them is that they get very stubborn brown stains, especially from carmelizing onions. I have tried Barkeepers Friend, bleach and enameled cast iron cleaner (Sur la Table and LC brands, which are made by the same company and appear to be the same product). Nothing took the stains out. What finally worked for me was to put a thin coat of dishwasher detergent (liquid Cascade)on the bottom of the pot, cover with water, and simmer lightly on the stove for about 20 minutes. That removed nearly all of the stains, but I don't think that the original glossiness will ever return. That's ok though....I tell myself that they were meant to be used, not sit on a shelf in pristine condition.

Blondelle, it happened before the Cascade....I had thought that the lack of glossiness was normal wear and tear, since it was my first piece and it happened gradually. The dullness looks patchy, and there is little to none of it along the edge of the bottom. I'm sure that I first noticed it after carmelizing onions.

I have had pieces of Le Creuset for 30+ years. I agree with everyone above who says the interiors discolor over time. If I can't remove discoloration with gentle simmering with water, then I let it remain. The cooking capability has never been affected. I am not a fan of the frying pans, but I love the soup pots and Dutch ovens. That's all I use for stews, beans and rice, etc.

I've had mine a dozen plus years. I, probably, shouldn't but when I get a stain, I put a little Chlorox Clean-up in the pan, add enough very hot water just to cover the stain, and let it sit for a couple hours. It's never failed to remove a stain and I can't see any compromise in the surface. It's probably not the best for the enamel but it hasn't removed the shine. Then, I run it through the D/W to make sure all of the chemicals are gone.

When i bought my first enameled LC pieces about 30 years ago they came with a cleaning instruction hang tag that described a combination of ingrediants you`d mix together then boil in the piece to remove the brownish stains and such,i wish i could remember the ingrediants and ratios cause i have a few stained pieces and i remember when i tried it long ago it worked perfectly,does anyone have any of those instuction???.i know Bleach heavily diluted was one of them,i guess the company doesnt include it anymore for risk of folks not doing it right causing more trbl and maybe the pieces made today dont hold up as well as the the older ones

Folks, thaks for all of your responses!
We found the following on the LC website:

Q: How do you clean the cookware?

A: Hand wash using a nylon brush or pad in warm, sudsy water to maintain the beauty of your finish.

Q: Can Le Creuset be washed in the dishwasher?

A: Yes, but not the pieces with wood handles. Since Le Creuset is very easy to clean, it is often easier to clean and dry by hand. We recommend hand washing in warm sudsy water with a nylon brush or pad to maintain the beauty of your finish.

Q: Can stains be removed without costly special cleaners?

A: Yes, by soaking 2 - 3 hours with a bleach solution of one teaspoon household bleach per pint of water.

I found it interesting that there is a new product being advertised on the website that is a cleaner and stain remover!

I may take a ride out to the company store here in Connecticut this weekend to see of they have the product. I might just give it a try.

Blondelle--I never got to the point where I developed the patina, I guess. One type of LC frying pan has a very smooth, gray enamel ("glissamail?") interior and I do use this for omelettes. I tried a nonstick fry pan, back in the days when I tried non-stick, and the non-stick coating bubbled. That was supposed to be their new generation, extra durable non-stick. LC replaced the pan and the same thing happened the first time I used it. I no longer use any non-stick, and find the regular LC enamel very sticky when frying, unless I use very large amounts of fat. I use well-seasoned cast iron, and I also use my stainless steel-lined Bourgeat copper pans with a little fat for frying. And, of course, a wok. I recently had to replace a lost, old, beautifully seasoned cast iron fry pan, and I did so with new Lodge Logic preseasoned cast iron, by the way. I really like it! How did you season your LC? (BTW I use a 15.5 qt black LC Dutch oven from an outlet store--very Halloweenesque!)

I burnt some,(a lot of), olive oil in a brand new Le Creuset french oven. After trying Barkeepers' Friend (that helped some) and simmering it filled with water (no help), I bought some Easy-Off (Fume Free) oven cleaner and put it outside for several hours. The brown stains just wiped out with a sponge.